Axial flow fan for external rotor

ABSTRACT

An axial flow fan for an external rotor, including at least: an axial flow blade, a support comprising an annular cylinder and multiple installation pins, and an external rotor motor comprising an external rotor. The installation pins are extended from the outside of the annular cylinder. The axial flow blade is disposed on the installation pin. The annular cylinder is fit on the external rotor of the external rotor motor. The flow fan features simple and convenient assembling, reliable connection, high production efficiency, low requirement for workers, and low production cost.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119 and the Paris Convention Treaty, this application claims the benefit of Chinese Patent Application No. 200920061726.0 filed on Jul. 27, 2009, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an axial flow fan, and more particularly to an axial flow fan for an external rotor.

2. Description of the Related Art

A typical structure for a conventional axial flow fan for an external rotor includes an air blade that is welded with external surface of a housing of the external rotor. However, requirements for a welding position and a welding direction of the air blade are stringent, and a high-level welding technology is needed, which cause high production cost and low production efficiency. A different structure employs a groove disposed on an outer surface of the housing, but installation of this axial flow fan is not reliable.

SUMMARY OF THE INVENTION

In view of the above-described problem, it is one objective of the invention to provide an axial flow fan for an external rotor that features simple assembling, high production efficiency, reliable connection, and low production cost.

To achieve the above objectives, in accordance with one embodiment of the invention, provided is an axial flow fan for an external rotor, comprising: an axial flow blade, a support comprising an annular cylinder and multiple installation pins, and an external rotor motor comprising an external rotor. The installation pins are extended from the outside of the annular cylinder, the axial flow blade is disposed on the installation pin, and the annular cylinder is fit on the external rotor of the external rotor motor.

In a class of this embodiment, the annular cylinder is formed by an annular body with an opening, and inner wall of the annular cylinder is interference-fit with outer wall of the external rotor.

In a class of this embodiment, a screw hole is disposed on the installation pin.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via nuts and bolts.

In a class of this embodiment, a through hole is disposed on the installation pin.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via riveting.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via welding.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via buckling.

In a class of this embodiment, the annular cylinder and the installation pin are integrally formed.

In a class of this embodiment, the annular cylinder is connected to the installation pin via welding, buckling, or riveting.

In accordance with another embodiment of the invention, provided is an axial flow fan for an external rotor, comprising an axial flow blade, a support comprising an annular cylinder and multiple installation pins, an external rotor motor comprising an external rotor, and an external convex ring. The installation pins are extended from the outside of the annular cylinder, the axial flow blade is disposed on the installation pin, the annular cylinder is fit on the external rotor of the external rotor motor, and the external convex ring is disposed between the annular cylinder and the installation pin.

In a class of this embodiment, the annular cylinder is integrally formed, and inner wall of the annular cylinder is interference-fit with outer wall of the external rotor.

In a class of this embodiment, a screw hole is disposed on the installation pin.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via nuts and bolts.

In a class of this embodiment, a through hole is disposed on the installation pin.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via riveting.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via welding.

In a class of this embodiment, the axial flow blade is disposed on the installation pin via buckling.

In a class of this embodiment, the annular cylinder and the installation pin are integrally formed.

In a class of this embodiment, the annular cylinder is connected to the installation pin via welding, buckling, or riveting.

Advantages of the invention are as follows: 1) the annular cylinder on the support is fit on the housing of the external rotor of the external rotor motor, and the inner wall of the annular cylinder is interference-fit with the outer wall of the external rotor, which results in simple assembling, reliable connection, high production efficiency, low requirement for workers, and low production cost; and 2) the external convex ring disposed between the annular cylinder and the installation pin is capable of increasing radial dimension and ensuring stable force transfer.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed description will be given below in conjunction with accompanying drawings, in which:

FIG. 1 is a schematic view of an axial flow fan for an external rotor of a first embodiment of the invention;

FIG. 2 is a cross-sectional view of FIG. 1 along a line C-C;

FIG. 3 is a schematic view of an axial flow fan for an external rotor of a second embodiment of the invention; and

FIG. 4 is a cross-sectional view of FIG. 3 along a line D-D.

DETAILED DESCRIPTION OF THE EMBODIMENTS

As shown in FIGS. 1 and 2, an axial flow fan for an external rotor of a first embodiment of the invention comprises an axial flow blade 1, a support 2 comprising an annular cylinder 21 and multiple installation pins 22, an external rotor motor 3 comprising an external rotor 31 and an inner stator 32, and an external convex ring 23.

The installation pins 22 are extended from the outside of the annular cylinder 21.

The axial flow blade 1 is disposed on the installation pin 22.

The annular cylinder 21 is fit on the external rotor 31 of the external rotor motor 3, and is integrally formed.

The external convex ring 23 is disposed between the annular cylinder 21 and the installation pin 22, and operates to increase radial dimension and to improve structural strength.

Inner wall of the annular cylinder 21 is interference-fit with outer wall of the external rotor 31.

A screw hole is disposed on the installation pin 22, and the axial flow blade 1 is disposed on the installation pin 22 via nuts 42 and bolts 41. Alternatively, a through hole is disposed on the installation pin 22, and the axial flow blade 1 is disposed on the installation pin 22 via riveting. Alternatively, the axial flow blade 1 is disposed on the installation pin 22 via welding or buckling.

The annular cylinder 21 and the installation pin 22 are integrally formed, or connected to each other via welding, buckling, or riveting.

As shown in FIGS. 3 and 4, an axial flow fan for an external rotor of a second embodiment of the invention comprises an axial flow blade 1, a support 2 comprising an annular cylinder 21 and multiple installation pins 22, and an external rotor motor 3 comprising an external rotor 31 and an inner stator 32.

The installation pins 22 are extended from the outside of the annular cylinder 21.

The axial flow blade 1 is disposed on the installation pin 22.

The annular cylinder 21 is fit on the external rotor 31 of the external rotor motor 3, and is formed by an annular body with an opening via a fastening device 5 or via welding.

Inner wall of the annular cylinder 21 is interference-fit with outer wall of the external rotor 31.

A screw hole is disposed on the installation pin 22, and the axial flow blade 1 is disposed on the installation pin 22 via nuts 42 and bolts 41. Alternatively, a through hole is disposed on the installation pin 22, and the axial flow blade 1 is disposed on the installation pin 22 via riveting. Alternatively, the axial flow blade 1 is disposed on the installation pin 22 via welding or buckling.

The annular cylinder 21 and the installation pin 22 are integrally formed, or connected to each other via welding, buckling, or riveting.

The invention features simple and convenient assembling, reliable connection, high production efficiency, low requirement for workers, and low production cost.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. 

1. An axial flow fan for an external rotor, comprising an axial flow blade; a support comprising an annular cylinder and multiple installation pins; and an external rotor motor comprising an external rotor; wherein said installation pins are extended from the outside of said annular cylinder; said axial flow blade is disposed on said installation pin; and said annular cylinder is fit on said external rotor of said external rotor motor.
 2. The axial flow fan of claim 1, wherein said annular cylinder is formed by an annular body with an opening; and inner wall of said annular cylinder is interference-fit with outer wall of said external rotor.
 3. The axial flow fan of claim 1, wherein a screw hole is disposed on said installation pin.
 4. The axial flow fan of claim 3, wherein said axial flow blade is disposed on said installation pin via nuts and bolts.
 5. The axial flow fan of claim 1, wherein a through hole is disposed on said installation pin.
 6. The axial flow fan of claim 5, wherein said axial flow blade is disposed on said installation pin via riveting.
 7. The axial flow fan of claim 1, wherein said axial flow blade is disposed on said installation pin via welding.
 8. The axial flow fan of claim 1, wherein said axial flow blade is disposed on said installation pin via buckling.
 9. The axial flow fan of claim 1, wherein said annular cylinder and said installation pin are integrally formed.
 10. The axial flow fan of claim 1, wherein said annular cylinder is connected to said installation pin via welding, buckling, or riveting.
 11. An axial flow fan for an external rotor, comprising an axial flow blade; a support comprising an annular cylinder and multiple installation pins; an external rotor motor comprising an external rotor; and an external convex ring; wherein said installation pins are extended from the outside of said annular cylinder; said axial flow blade is disposed on said installation pin; said annular cylinder is fit on said external rotor of said external rotor motor; and said external convex ring is disposed between said annular cylinder and said installation pin.
 12. The axial flow fan of claim 11, wherein said annular cylinder is integrally formed; and inner wall of said annular cylinder is interference-fit with outer wall of said external rotor.
 13. The axial flow fan of claim 11, wherein a screw hole is disposed on said installation pin.
 14. The axial flow fan of claim 13, wherein said axial flow blade is disposed on said installation pin via nuts and bolts.
 15. The axial flow fan of claim 11, wherein a through hole is disposed on said installation pin.
 16. The axial flow fan of claim 15, wherein said axial flow blade is disposed on said installation pin via riveting.
 17. The axial flow fan of claim 11, wherein said axial flow blade is disposed on said installation pin via welding.
 18. The axial flow fan of claim 11, wherein said axial flow blade is disposed on said installation pin via buckling.
 19. The axial flow fan of claim 11, wherein said annular cylinder and said installation pin are integrally formed.
 20. The axial flow fan of claim 11, wherein said annular cylinder is connected to said installation pin via welding, buckling, or riveting. 